Telephone-transmitter.



PATENTED MAY 28, 1907.y

No. 555,395.v

' OTTALK.

TELEPHONE TRANSMITTER.

APPLIOATIO I ILED JULY 2. 1906 un 'ran srnrnsj ernfsr orties;

OSCAR F. FALK, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO AMERICAN TELEPHONE AND TELEGRAPII COMPJINY,` A. CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented May 28, 1907.

(lriginal application le. July 1,-1905,Scrial N- 267,El62. Divided and this application filed July 2,1906. Serial No.324,5 25.

Todi?, whoml t netti/,concern Beit known that I, Osons F. FALK, residing at Boston, in the county 'of Suffolk and State oi` Massachusetts, have invented cer- .tain- Improvements in Telephone-Transmitters, of which the following is aspecication. The present invention relates to improvements 1n telephone transmitters, this application being a division of my prior applicapactly together and readily separable for repairs or adjustments, 'the device as a whole or unit being readily attaphable to or detachable from standard telephonie instruments or apparatus.

In the accompanying drawing-I have illusy trated the improved transmitter, in which is noW believed to be its preferred iorin,and as forming part of a hand-set, the transmitter having been especially designed for such-use.

Fi re '1 shows in elevation a hand-set of Whic themproved transmitter forms a part.

.Fig-2 is a vertical sectional vietvthrough.v

the transmitter end of the hand-set; and Fig. 3ds a 'similar sectional view4 showing a modified :Corm oiftransmitter.

H is the hollow handle-bar of the hand-set l A is the outer case or shell oi the transmitter, secured to the hollow handle-bar H bv screws s, s, as shown.

. case A secured thereto by screws s, s.

C is the mouth-piece of the transmitted screwed into the cover and furnished with a perforated protector, as shown.

D is the transmitter diaphragm secured to .an inner case or metallic shell E by a dampening fastener, such as an elastic rubber dampe band F, the said diaphragm and inner case, eing separated by a paper lring G,

B is a cover for said while l is a ring oi mica, separating the assembled diaphragm, inner case and rubber band from the cover B. This combination of inner ease, diaphragm, rubber-band, etc., together with the granular button, next to be described, Within the inner case, is held in position by a spring S secured to a blocl; orI

projection on the inside of the flange B of the cover by a screw, as shown, and forms a unitary device or portable-article comprising all oi the essential parte of the transmitter heid compactly together, which Vdevice as a whole is readily attachable to or detachable from any standard instrument. The bearing end of the spring has a rubber hood, as shown,

and presses against the rubber band Foutside oi Ithe inner case. V is a variable resistance granular carbon button, consisting 'of a.l

screw S3 with one Wire of the transmitting cirv cuit, 'While the iront electrode is in conduct- I ive connection with the other Wire oi the transmitting circuit at screw si, by means oi a Wire VV conductively connected with 4the frontelectrode and passing through an insulated bushing in the iront part of shell V and in said inner case.

' L is a rigid shank projecting from the front electrode of the button V. Its outer end, in

one form of the hand-set, Fig. 2, projects through a slightly up-set portion oi' the diaphragm at the center of the diaphragm and is secured fby a thumb-screw' M. modiiication shown in Fig. 3, the shank L is bent 'so that its end passes readily through the center of the dia hragm and is secured by a thumb-screw M inthe ordinary manner. The straight-tubed mouth-piece used in either construction allows sounds to fall u on the diaphragm substantially Ji'ee from re ection.

In both embodiments of the invention In the IOGM Figs. 2 and 3, the carbon-button is supported iIO lation to the diaphragm. This isof particu lar importance when the transmitter is used in a hand-set, such as explained in' my original application above mentioned.

I claim:

In a telephone transmitter, the combinationof acase or shell; a diaphragm secured to and closing said shell; a variable resistance button inclosed Within and supported by said shell' in a position oblique to the diaphragm, said button having electrodes and containing granular carbon between the same, one of the electrodes being secured to the diaphragm and the other to the wall of theshell, the whole constituting a unitary device* coinpris- 15 i ing the severa]v parts of the transmitter.

in testimony whereof, have signed my naine to this specii'ication in the presence of two subscribing Witnesses, this twenty third day of June 1906.

OSCAR F. FALK. Witnesses: y*

GEO. WILLIS PIERCE, JOSEPH A. GATELY. 

